<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			ul>li{
				width: 240px;
				height: 50px;
				line-height: 50px;
				list-style: none;
				background: #f9d217;
				margin: 3px 0 ;
				transition-duration: 1.5s;
				color: #333326;
			}
			span{
				margin-left: 20px;
			}
			li:hover{
				background: #ed4f4f;
				width: 320px;
				border-radius:0 50px 50px 0 ;
				color: white;
			}
		</style>
	</head>
	<body>
		<nav>
			<ul>
				<li><span>首页</span></li>
				<li><span>案例展示</span></li>
				<li><span>新闻中心</span></li>
				<li><span>问题反馈</span></li>
				<li><span>联系我们</span></li>
			</ul>
		</nav>
	</body>
</html>
